Valve bag



Oct. 5, 1965 J. PELCE 3,209,984

VALVE BAG Filed March 31, 1964 United States Patent 3,209,984 VALVE BAG Jean Pelc, Flixecourt, Somme, France, assignor to Compagnie Industrielle des Textiles et Emballages Plastiques C.I.T.E.P., Paris, France Filed Mar. 31, 1964, Ser. No. 356,313 Claims priority, application France, Apr. 5, 1963, 930,585, Patent 1,273,468 3 Claims. (Cl. 229-625) Valve bags are already known which comprise a piece added on a wall of the bag so as to form with this wall a pocket of which the bottom is cut to permit the introduction of the materials to be bagged.

The piece is more particularly added on the outer face of the bag. This method permits of automatizing the manufacture of the bag from a sheath, which is difficult if not impossible, when the piece is secured internally of the bag.

The bags under consideration may be made from thermoplastics materials as well as from any other material such as jute, cotton, paper, metal sheets, compound materials for example pitch-glued jute and paper, polyethylenelined paper, etc.

The present invention is an improvement to the valve of such bags, with a view to render perfect the fluid-tightness thereof.

In conventional valve bags, the closure is obtained when the bagged product exerts a pressure on the inner wall of the valve, which it pushes against the outer wall thereof, thus closing the orifice for introducing the material into the bag.

The inconvenience is that this closing system is not perfect. The valve, even after its walls have been applied against each other by the pressure of the bagged product, still constitutes a passage, very small but nevertheless existing, between the two media, internally and externally of the bag, into which this valve opens without any real sealing effect.

To avoid this drawback, the invention has for its object to provide a bag possessing a valve added on the outer wall of the bag, this valve being constituted by a sleeve of which one portion, in the vicinity of the valve inlet, is free and of which the other portion is welded to the bag, on the one hand, along the lateral edges of the sleeve, on the other hand, on either side of the slit, so that the lips of the sleeve, on this side, are secured to the bag while surrounding completely this slit, that is to say, the lower wall of the sleeve laid flat is secured along the slit, on this side of the slit in relation to the aforesaid two weld seams, whilst the end of the upper wall of the sleeve is secured beyond the slit.

The operation of this valve is as follows: The filling nozzle is introduced into the sleeve. At the bottom of this sleeve, the nozzle penetrates into the bag through the slit. Once the bag has been completely filled and the nozzle removed from the bag, the absolute fluid-tightness of the bag may be ensured in two different manners:

(1) Either closing the free portion of the sleeve, for example by effecting an end welding, thus providing an absolute sealing;

(2) or simply folding the free portion of the sleeve under its portion secured to the bag, thus providing a closure of the tobacco pouch type.

This sleeve, constituting the subject-matter of the invention, may be made from the same material as the bag, or from any other material. It is secured to the bag by any suitable process such as welding, adhesive material, etc.

A specific form of embodiment of a valve bag provided with the sleeve according to the invention is to be described hereafter, by way of non-limiting example, with reference to the accompanying drawing, in which:

FIGURE 1 is a fragmentary plane view of the bag with parts broken away.

FIGURES 2 to 5 are sectional views taken respectively along the lines II-II, IIIIII, IV-IV and V-V of FIGURE 1.

The bag concerned here is a valve bag 6 of thermoplastics material with a valve added externally of the bag.

This valve is located along the upper edge 2 of the bag.

For the manufacture of the bag constituting the subject-matter of the invention one may start, for example, from a sheath of polyethylene or any other thermoplastic material, this sheath being provided or not with bellows.

(1) First, the valve is formed on one of the walls of the sheath prior to the manufacture of the bag proper. To this end:

(a) A slit 5, either straight or consisting of a broken or curved line, is formed in the wall 4 which supports the valve, at the location of the bottom of the valve of the future bag.

(b) A sleeve 317 is prepared, which has the following particularity: when it is laid flat, at one of its ends, which is its lower end, its lower wall 17 is slightly shorter than its upper wall 3.

(c) This sleeve 3-17 is secured on the bag. This sleeve is made, for example, from the same material as the bag. The two superposed walls of the sleeve are secured on one face 4 of the bag by means of the lateral weld seams a and c towards the top 2 of the bag; the registering weld seams a and 0 run only along one portion 19 of the length of the sleeve, from its lower end; the lower wall 17 of the sleeve is secured by means of a weld seam d and the upper wall 3 of the sleeve by means of a weld seam 11, these weld seams d and b being located on either side of the slit 5 formed in the wall 4 of the bag and having a length slightly inferior to the width of the walls 3 and 17 of the sleeve, the wall 3 overlapping the slit. This fixation of the sleeve 3, 17 is performed with the assistance of a suitable electrical heating machine comprising an electrode of adequate shape.

In a somewhat longer but easier method, one starts, for forming the sleeve, from two pieces of slightly different dimensions which will form the lower wall 17 and the upper wall 3 of the sleeve. In a first step, the lower wall 17 of the sleeve is secured on the bag, by means of the weld seams a, c and d, and, in a second step, the sheet forming the upper wall 3 of the sleeve is secured by the weld seams a, b and 0.

At the same time as this second operation in this second method, or at the end of the operations described hereabove in connection with the first method, the sleeve proper is completed in its upper free portion 18 by welding the two sheets, lower and upper, to each other, along their lateral edges, by weld seams e and f.

(2) After the valve has been positioned, the bag proper is manufactured.

If the sheath has not been cut beforehand, it is cut at the location corresponding to the top 2 of the bag and to the bottom of the bag. Subsequently, the top and the bottom of the bag are closed by welding In a faster process, the sheath is cut and the top and the bottom of the bag are welded during a same operation with the assistance of an appropriate machine.

The bag is filled by introducing the filling nozzle in the direction of the arrows f1 and f2 into the inner space 7 of the sleeve and then, through the slit 5, into the interior 8 of the bag. Once the bag has been filled and the nozzle removed, the top of the free upper portion of ing, gluing, stapling, folding, etc., a satisfactory sealing of the filled bag being thus ensured.

Modifications of detail concerning for example the shape of the sealing piece 17 and of the added piece 3 forming the outer portion of the valve, as well as the position of the valve on the wall of the bag, may be brought to the device described hereabove by way of example, without thereby departing from the field of the invention.

What I claim is:

1. In a valve bag comprising a separate piece added externally on a wall of the bag and welded thereto along stituting a valve for the introduction of the materials to be bagged and the closure of the filled bag, the improvements consisting of an extension of said piece, not welded to said bag wall, on the inlet side of said pocket, and

of a second piece interposed between said bag wall and said first piece including said extension thereof up to the top edge of said extension, welded laterally to said first piece and said extension thereof, welded laterally to said bag Wall along the same length as said first piece and welded along its lower edge to said bag wall above said slit, the improved valve being thus constituted by a sleeve 4 of which the lower portion adjacent to said slit is welded laterally to said bag wall up to a substantial length above said slit, thus forming a pouch between said lower portion of said sleeve and said bag wall, and of which the upper portion is not Welded to said bag wall and constitutes the valve inlet, which is closed by being folded and inserted into said pouch.

2. A valve bag according to claim 1, wherein said sleeve is made from the same material as the bag itself. 3. A valve bag according to claim 1, wherein said sleeve is made from another material than the bag itself.

References Cited by the Examiner UNITED STATES PATENTS 2,147,970 2/39 Du Bois. 2,566,838 9/51 Hurt 1509 X 2,821,338 1/58 Metzger 229-62.5

OTHER REFERENCES Bischof, German application 1,004,034, printed March 1957.

JOSEPH R. LECLAIR, Primary Examiner.

25 GEORGE O. RALSTON, FRANKLIN T. GARRETT,

Examiners. 

1. IN A VALVEW BAG COMPRISING A SEPARATE PIECE ADDED EXTERNALLY ON A WALL OF THE BAG AND WELDED THERETO ALONG THREE SIDES SO AS TO FORM WITH THIS WALL AN EXTERNAL FLAT POCKET, AND A SLIT IN SAID WALL INSIDE SAID POCKET AND NEAR THE BOTTOM THEREOF, SAID FLAT POCKET WITH SAID SLIT CONSTITUTING A VALVE FOR THE INTRODUCTION OF THE MATERIALS TO BE BAGGED AND THE CLOSURE OF THE FILLED BAG, THE IMPROVEMENTS CONSISTING OF AN EXTENSION OF SAID PIECE, NOT WELDED TO SAID BAG WALL, ON THE INLET SIDE OF SAID POCKET, AND OF A SECOND PIECE INTERPOSED BETWEEN SAID BAG WALL AND SAID FIRST PIECE INCLUDING SAID EXTENSION THEREOF UP TO THE TOP EDGE OF SAID EXTENSION, WELDED LATERALLY TO SAID FIRST PIECE AND SAID EXTENSION THEREOF, WELDED LATERALLY TO SAID BAG WALL ALONG THE SAME LENGTH AS SAID FIRST PIECE AND WELDED ALONG ITS LOWER EDGE TO SAID BAG WALL ABOVE SAID SLIT, THE IMPROVED VALVE BEING THUS CONSTITUTED BY A SLEEVE OF WHICH THE LOWER PORTION ADJACENT TO SAID SLIT IS WELDED 